Histological evaluation of no‐cross‐link and cross‐link collagen membranes, in rats

Background Absorbable collagen biomaterials have biocompatibility and ability to promote wound repair, in addition to their natural biological potential, which enables a favorable environment for regeneration, and therefore, their use in the technique is highly preferred among clinical professionals. However, the degree of rapid reabsorption of collagen, as well as the associated specific inflammatory process, is a constant concern for clinicians and researchers. Aim/Hypothesis Histological evaluation of the behavior of two absorbable biomaterials composed of type I collagen, with different cross-links grafted to the dorsal muscular tissue of rats. Material and Methods The sample consisted of 13 animals, Holtzman rats (male 250 g), divided into 5 experimental groups, with sacrifice periods of 2 h (n = 1), 1, 5, 10 and 15 days (n = 3). 5 mm2 of the biomaterial, cross-link (CL) and no cross-link (NCL) collagen membrane, was inserted in the dorsal muscular tissue of the animals, being used the Masson's trichrome dye for the histological analysis. Results NCL showed integrity at 5 days and complete degradation at 10 days, when the remission of the inflammatory process detected during its degradation was observed, without presenting foreign body reactions. The CL membrane presented an inflammatory process with intermittent peaks of low and high intensity, and also with no foreign body reaction, but with minimal degradation, maintaining its semi-intact structure isolated by fibrous connective tissue at 15 days. Conclusion and Clinical Implications In the evaluated period, it was concluded that the NCL degradation was better biocompatible, with the CL being more stable. The stability over a longer period is desirable in the GTR technique. Further studies for CL over a longer period of time are needed to evaluate its complete degradation and temporal biocompatibility.